It sounds like you could use Google's live traffic info to augment your own predictions. You should be fine with just a few API calls. This would be pretty cheap - perhaps even within the free tier.
Which part of the ToS (that isn't getting violated already)?
The real problem with this approach is that you will never know when real time is conflicting with historical unless you're calling the API constantly anyway
> (c) No Creating Content From Google Maps Content. Customer will not create content based on Google Maps Content.
> (d) No Re-Creating Google Products or Features. Customer will not use the Services to create a product or service with features that are substantially similar to or that re-create the features of another Google product or service.
For the use case described in the article it sounds just fine. The content part is a big vague. If read very broadly it would be super prohibitive. Perhaps it is?